Get rid of promotedType=none annotations

pkg/front_end/testcases/inference/future_then_upwards_3.dart

Index: pkg/front_end/testcases/inference/future_then_upwards_3.dart
diff --git a/pkg/front_end/testcases/inference/future_then_upwards_3.dart b/pkg/front_end/testcases/inference/future_then_upwards_3.dart
index 3c7f6947abc52a940f4bebe2e468e861da2e6707..4c658a904f1499278a29f5a0b2ea8786ee388633 100644
--- a/pkg/front_end/testcases/inference/future_then_upwards_3.dart
+++ b/pkg/front_end/testcases/inference/future_then_upwards_3.dart
@@ -18,7 +18,7 @@ void main() {
   var /*@type=Future<double>*/ f =
       foo(). /*@typeArgs=double*/ /*@target=Future::then*/ then(
           /*@returnType=double*/ (/*@type=dynamic*/ _) => 2.3);
-  Future<int> f2 = /*error:INVALID_ASSIGNMENT*/ /*@promotedType=none*/ f;
+  Future<int> f2 = /*error:INVALID_ASSIGNMENT*/ f;
 
   // The unnecessary cast is to illustrate that we inferred <double> for
   // the generic type args, even though we had a return type context.